Bollocks

Just forgot my dads birthday. Now, this wouldnt be such a big deal as Im not that hot at remembering dates (unless you are in my outlook calander at work then you are fucked) but dad takes this personal.
Our family have NEVER made a big deal out of birthdays. Man, he forgot my 16th,had a car crash on my 21st and I watched him go into Asdas to buy a card for me and write it on the roof of the car this year.
I forgot my step dad's and I apologised and he was cool.
Ok my dad has 2 daughters and they both forgot but as I said it was never a big deal.
I feel fucking awful, and a grudge will be held. But sometimes its a cruel reminder that our family is never as tight knit as some would hope. If you dont put into something then you really dont get much out of it.
This has nothing to do with love. Its not a reflection on how much you love someone. Thats a completly different ball game. This is down to my head being up my arse and I forgot. Full stop.
Seeing him aprox 4 times a year doesnt help matters either.
Am I now just making excuses to make myself feel better?
Possibly, I feel awful.